A
materials list, including cost and where you will purchase/obtain
the items
- Mason Jar Straws $2 Each/Michael's
- Rubber Bands $3/Michael's
- Mouse Trap $1.99/Home Depot
- CDs $1/Garage Sale
- Fishing Rod $1
- Plastic hand cuffs $3/Home Depot
What was your objective? What were you trying to accomplish?
A justification statement, describing why you have made these design decisions.
We have decided to build a light car in order for it to be able to travel at a high velocity. The hollow straws and the fishing rod will have little impact on the thin discs so it doesn't weigh down on the wheels. When we are able to center the force on the straws, the balance will result in the object traveling in a straight direction, fast. The hot glue will help make sure the parts of our car will be held secure until the day of the ramp test. We decided to use only one mouse trap with a short rod because using two would just waste energy and reduce the chances of the car traveling at its maximum speed in tandem. We also made sure to not put the weight over the drive axle, but in the front. Doing so increased the speed since we were going uphill. Adding rubber bands on the wheels would add friction and propel the car to go faster against the wooden surface. Our overall objective was to create an offensive car that would simply win the round by getting to the top of the ramp before the other car. We were able to accomplish this goal after several test runs, modifications, and our willingness to do the best we can.
good! Equations:
good! Equations:
- f*t= mvf-mvi
- mvi1(v1i)+mvi2(v2i)=mv1f*m1f
- Forces: What forces will act on your car? How will the value of the force affect the performance of your car?
The forces of gravity, normal force, force of lever (mouse trap), and the force of friction will be acting on the car. The normal force will determine how fast the car will be able to go. Force of the mouse trap will also play a factor in the velocity and acceleration during the competition. If a great force is applied, the further the car would travel. The force of friction will be acting against the car to slow it down since the ramp will be wood and also uphill.
- Motion: What velocity changes will your car undergo during the competition? Will your car accelerate? How and at what points?
Greater acceleration can be achieved by increasing the power torque, using a short lever arm, and having a light weight car. The car will accelerate in its starting points after setting off the mouse trap, when there is the most force acted upon the car from the direct power torque. However, we are expecting the velocity to decrease as the car approaches the top due to the slanted, uphill angle of the ramp.
- Mass/Weight: How do the mass and weight of your car affect its performance during the competition?
Having a lightweight car will determine the amount of velocity the car will be traveling at. Because the wheels will have less weight to carry than most cars, there will be less pressure on the CDs and more room for the wheels to turn. The negative side of the light weight is that it might get ran over by a car that is heavier. Hopefully this doesn't have to happen if the car is able to reach the top of the ramp before the competitor's car does.
- Newton’s Laws: How do Newton’s 1st and 3rd Laws apply during the competition?
1st Law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. The car will remain at rest on the bottom of the ramp until a force is acted upon the object (in this case, the mouse trap lever.) Or, it will continue to travel in a straight line until the car comes into contact with the car coming from the opposite direction during the competition. 3rd Law states that for every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. When the two cars collide at the top of the ramp, both would experience the equal amount of force. As our car would push the other car, the other car would push ours back. nice
- Momentum/Impulse: Describe what will happen at the top of the hill, in terms of momentum and impulse.
Momentum can be calculated as mass times velocity. The greater the mass or velocity, the more momentum the object will have. Because our car will be focusing more on speed, it could have more momentum than the other car. When the two cars crash at the top of the hill, they will experience equal and opposite forces as well as same time of impact. But, if the cars vary in masses, they will experience different changes in velocity or acceleration. This determined who wins the round during the competition.
- Did you make any modifications to your original plans before you ran it on the ramp? If so, describe them and explain why you made these modifications. The explanation should be in terms of physics concepts as you used in the justification statement.
There were no major modifications made to our original plans, besides the wheels. Because we weren't able to find small wheels, we used CDs. Large wheels increase the rotational inertia while small wheels do not. They were helpful because they were thin; when going up hill, we wanted to divert all energy into a small surface area.
- Describing your car’s run on the ramp in terms of displacement, velocities and accelerations. Did it get up to speed quickly and then slow down? Did it get up to speed slowly? Did it vary its acceleration (speeding up, slowing down, etc.)?
In terms of displacement, our car was able to get to the top of our ramp every time. As we would set off the mouse trap lever, the car would gradually decrease in velocity as it approaches the top. The maximum acceleration of a mousetrap vehicle depends on the amount of grip or traction the vehicle's drive wheels have on the road surface. It was important to make sure the lever was able to strike from 180 degrees to ensure the maximum force exerted on the car. The length of the lever also determined the car's displacement as well as velocity. - Discussing the car’s performance on the ramp in terms of your plans. Did you plan certain features into the car and did the car’s performance benefit from these features? Or did the car not perform as you had planned and hoped? If so, what do you think went wrong in terms of planning or performance? At the minimum, you should discuss the plans you discussed in the justification statement. But you may also discuss other plans that unfolded as you constructed your car.
I planned on making the car light as possible with light, plastic materials. Because we were able to center the straws and the handcuffs to the center of the object, the car moved in a straight line along the ramp. Because we made the hand cuffs loose, the straws that were glued to the wheels were able to move freely once propelled by the lever. The car performed as well as we had hoped, until the Sweet Sixteen round when we were met by a car that weighed more than ours. We realized that even though our car was pretty light, the handcuffs were weighing down on the wheels and did not let the car move as fast as it could have. We had trouble finding a way that would keep the mouse trap stable while the wheels turned on both sides.
- Will you make any further modifications to the car after its performance on the ramp? If so, what? Explain in terms of physics equations as in the justification statement. If you didn’t make any further modifications, explain why you were satisfied with the car as it is.
We didn't make any further modifications due to the fact that our car was able to get to the top of the ramp fast and in a straight direction. This was our main objective and that was what our car was able to accomplish.
Describe
each of your car’s races. Describe your reaction to the
competition.
Since we were automatically advanced into the second round, we were relieved to find out that we would have less rounds to go through. In the first actual race, the other group forfeited. Then, the next team's car wasn't able to move more than 5 inches from the starting position. Until this point, we were surprised at how lucky we were getting. But we knew that there were impressive cars in the contest and that there was tough challenges ahead of us. Before the next round, one of our friends broke one of our wheels of so we had to attempt to put the wheel back in its place without an access to hot glue. This could have also had an affect on our loss in the next round. We were matched up with a car that was twice our car's weight. Once the cars met at the top, the other car ran over ours. We were crushed because if we had won that round, we would have advanced to the Elite Eights. Overall, this was a fun experience. My partner and I learned a lot about mouse-trap cars and were impressed at how our peers were able to construct cars.so close!!!
Ramp Test Evaluation
Were you
successful? If so, why? If not, why not? Remember to use physics
language in your descriptions. In general, was there a car type that
was more successful than others? What features did the winning cars
have that made them successful? If you were to do this project
again, what specific things would you improve? How?
In my opinion, we were successful, because we were able to construct an actual propelled car from scratch. We didn't think our car would be very sturdy or get as far into the competition as we did. Because it was light, but fast it was able to win the rounds where the other car had less velocity or acceleration. The types of cars that were the most successful were the ones that were heavy but also fast. The wooden cars seemed to do the best in the competition. Those ones had small wheels, centered weight, and a powerful propeller. If we were to do the project again, we would construct the car so that it would be more stable and heavy so that it would be able to go against a car that's heavier than ours.
In my opinion, we were successful, because we were able to construct an actual propelled car from scratch. We didn't think our car would be very sturdy or get as far into the competition as we did. Because it was light, but fast it was able to win the rounds where the other car had less velocity or acceleration. The types of cars that were the most successful were the ones that were heavy but also fast. The wooden cars seemed to do the best in the competition. Those ones had small wheels, centered weight, and a powerful propeller. If we were to do the project again, we would construct the car so that it would be more stable and heavy so that it would be able to go against a car that's heavier than ours.


